In the electronics industry, as products such as cell phones and camcorders become smaller and smaller, increased miniaturization of integrated circuit (IC) packages has become more and more critical. At the same time, higher performance and lower cost have become essential for new products.
Usually, many individual integrated circuit devices are constructed on the same wafer and groups of integrated circuit devices are separated into individual integrated circuit die.
In order to interface an integrated circuit die with other circuitry, it is common to mount it on a leadframe or on a multi-chip module substrate that is surrounded by a number of lead fingers. Each die has bonding pads that are then individually connected in a wire bonding operation to the lead fingers of the leadframe using extremely fine gold (Au) or aluminum (Al) wires. The assemblies are then packaged by individually encapsulating them in molded plastic, epoxy, or ceramic bodies.
One approach to putting more integrated circuit dies in a single package involves stacking the dies with space between the dies for wire bonding. The space is achieved by means of a thick layer of organic adhesive or in combination with inorganic spacers of material such as silicon (Si), ceramic, or metal. Unfortunately, the stacking adversely affects the performance of the package because of decreased thermal performance due to the inability to remove heat through the organic adhesive and/or inorganic spacers. As the number of dies in the stack increases, thermal resistance increases at a faster rate. Further, such stacked dies have a high manufacturing cost.
Another approach is to put more integrated circuit dies side-by-side in a single package but this results in packages taking up large areas on the printed circuit boards.
Each attempt to reduce the size of the integrated circuit package tends to create additional problems with cost, heat transfer, and electrical performance.
Across virtually all applications, there continues to be growing demand for increasing capacity and increasing performance of integrated circuit memory. The seemingly endless restrictions and requirements are no more visible than with products in our daily lives. Smaller and denser integrated circuits are expected in many portable electronic products as well as in many larger electronic systems. As the demand grows for smaller electronic products with more features, manufacturers are seeking ways to include more capacity with small product dimensional form factors.
Thus, a need still remains for an integrated circuit package system to provide improved density and manufacturing yield. In view of the increasing demand for improved integrated circuits and particularly more integrated circuit package density, it is increasingly critical that answers be found to these problems.
Solutions to these problems have been long sought but prior developments have not taught or suggested any solutions and, thus, solutions to these problems have long eluded those skilled in the art.